Method for Transmitting Control Information

ABSTRACT

The present invention discloses a method for transmitting control information. Downlink control information is categorized into common control information and dedicated control information. A physical broadcast channel is extended by dividing a common control channel domain into a plurality of narrowband sub-control channel domains by adding a position identifier. Before a connection is established, the common control information is sent, according to the position identifier, in each sub-control channel domain of the common control channel domain. After the connection is established, a sub-control channel domain with a channel state that complies with a set standard is selected, according to a channel state of each sub-control channel domain, for sending the dedicated control information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation U.S. patent application Ser. No.14/272,142, filed on May 7, 2014, which is a continuation ofInternational Application No. PCT/CN2012/084189, filed on Nov. 7, 2012,which claims priority to Chinese Patent Application No. 201110348298.1,filed on Nov. 7, 2011. All of the aforementioned patent applications arehereby incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of communicationstechnologies and, in particular embodiments, to a method fortransmitting control information.

BACKGROUND

With the development of application of the Internet of Things, thenumber of used Internet of Things devices increases constantly andrapidly. As an important connection link for bearing data communicationbetween the Internet of Things devices, a communications network bears aconstantly increasing amount of data and a constantly increasing numberof service types.

During the development process of the Internet of Things, to decrease acost of Internet of Things terminals to accelerate popularization of theInternet of Things, an operator proposes a concept of a low costterminal in a long term evolution (LTE) conference of the thirdgeneration partnership project (3GPP).

A low cost terminal only supports small bandwidth, such as 1.4 M, andtherefore may also be called a narrowband user terminal. The low costterminal can largely save a cost of an Internet of things terminal. Formost Internet of things devices, small bandwidth can meet their needs ofdata transmission. Therefore, an Internet of things terminal, as a lowcost terminal, can largely decrease a device cost without affectingcommunication, and it can be further predicted that the low costterminal has a bright prospect in the Internet of things.

In the prior art, there is a technical solution that a position of a newdownlink narrowband control channel domain is notified by using aphysical broadcast channel (PBCH) for a low cost terminal to use, sothat the low cost terminal only occupies a part of a frequency band of abroadband when performing broadband access, so as to save bandwidth andreduce receiving and processing complexity.

However, the inventor finds in researches that although many Internet ofThings services only require a low transmission rate, controlinformation of the services has a high priority. Particularly, sendingand receiving conditions of downlink control information may directlyaffect system performance. Physical resource blocks (PRB) in anarrowband system in the prior art have a small frequency interval andhigh relevance, and may be in deep fading at the same time. As a result,control information transmitted in the narrowbands cannot be accuratelyreceived or sent by some terminals in deep fading. Therefore, the priorart at least has a defect. In that a control channel of a low costterminal has poor reliability of control information transmission,thereby affecting system performance.

SUMMARY

In view of this, embodiments of the present invention provide a methodfor sending downlink narrowband control information in a broadbandsystem, where a sub-control channel domain with a good channel state isselected to send the control information, thereby improving reliabilityof control information transmission on a control channel for a low costterminal.

Therefore, an embodiment of the present invention provides a method fortransmitting control information. Downlink control information iscategorized into common control information and dedicated controlinformation. A physical broadcast channel is extended by dividing acommon control channel domain into a plurality of narrowband sub-controlchannel domains by adding a position identifier used for indicating atime-frequency position of the common control channel domain. Before aconnection is established, the common control information in eachsub-control channel domain of the common control channel domain is sentaccording to the position identifier. A random access resource dedicatedfor a narrowband user terminal is allocated and the narrowband userterminal in system information is notified. After the connection isestablished, according to a channel state of each sub-control channeldomain, a sub-control channel domain with a channel state that complieswith a set standard is selected for sending the dedicated controlinformation and a channel instruction is sent. The channel instructionis information used by a base station to instruct, according to thechannel state of each sub-control channel domain, the narrowband userterminal to select a sub-control channel domain that complies with theset standard.

In addition, an embodiment of the present invention further providesanother method for transmitting control information. An extendedphysical broadcast channel and common control information are receivedaccording to a preset position identifier. A random access resource issent. After a connection is established with a network, a channelquality state is reported a channel instruction is obtained and acorresponding sub-control channel domain is listened to according to thechannel instruction. The position identifier is a position identifieradded by a base station by extending a physical broadcast channel andused for indicating a time-frequency position of a common controlchannel domain, so as to divide the common control channel domain into aplurality of narrowband sub-control channel domains. The channelinstruction is information used by the base station to instruct, byextending the physical broadcast channel and according to the channelstate of each sub-control channel domain, a narrowband user terminal toselect a sub-control channel domain.

To sum up, in the technical solutions provided by the embodiments of thepresent invention, a channel state selection scheme is set, so that whensending downlink control information to a narrowband user terminal, abase station selects a sub-control channel domain with good connectionquality and low load and instructs the narrowband user terminal toselect a sub-control channel domain that complies with a set standard,thereby effectively improving reliability of control informationtransmission on a control channel for the narrowband user terminal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flowchart of a method for transmitting controlinformation according to an embodiment of the present invention;

FIG. 2 is a schematic flowchart of another method for transmittingcontrol information according to an embodiment of the present invention;

FIG. 3 is a schematic flowchart of another method for transmittingcontrol information according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a manner of notifying by using an RRCmessage according to an embodiment of the present invention;

FIG. 5 is a schematic flowchart of another method for transmittingcontrol information according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of another manner of notifying by using anRRC message according to an embodiment of the present invention;

FIG. 7 is a simplified block diagram of a base station according to anembodiment of the present invention; and

FIG. 8 is a simplified block diagram of a user terminal according to anembodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the present invention provide a method for transmittingcontrol information, which is described in the following with referenceto the embodiments.

In the embodiments, a mentioned low cost terminal is a narrowband userterminal that emerges to save broadband network bandwidth occupied by aterminal. To improve reliability of control information transmission ona control channel for the narrowband user terminal, referring to FIG. 1,a first embodiment of the present invention provides a method fortransmitting control information.

S01: Categorize downlink control information into common controlinformation and dedicated control information.

In a base station shown as FIG. 7, to use different operation methodsfor different control information, control information needs to becategorized first, and specifically, downlink control information may becategorized into two types: common control information and dedicatedcontrol information.

The common control information may specifically include: controlinformation used for scheduling system information (SI), controlinformation used for scheduling a paging message, and a controlinformation RAR message used for scheduling a random access response(RAR) message.

The dedicated control information may specifically include dedicateddownlink control information after the narrowband user terminal, shownas FIG. 8, is in a connection state, such as control information ofnarrowband resource allocation and other control information.

S02: Extend a physical broadcast channel: A common control channeldomain includes a plurality of narrowband sub-control channel domains byadding a position identifier used for indicating a time-frequencyposition of the common control channel domain, where the time-frequencyposition of the common control channel domain may be a specifictime-frequency position, such as a specific subframe or frequency, forexample, a time-frequency resource in a subframe of a multimediabroadcast single frequency network (MBMSFN) is provided for the commoncontrol channel domain to use.

To enable a plurality of narrowband control channels to worksimultaneously in a broadband network, in this embodiment, the commoncontrol channel domain is divided into a plurality of narrowbandsub-control channel domains. The plurality of sub-control channeldomains coexists in a broadband network and therefore need to bedistinguished and identified. Therefore, in this embodiment, thephysical broadcast channel is extended, and the position identifier usedfor indicating the time-frequency position of each sub-control channeldomain in the common control channel domain is added. In this way, acorresponding sub-control channel domain can be found by using theidentifier.

S03: Before a connection is established, send, according to the positionidentifier, the common control information at a time-frequency positionof each sub-control channel domain of the common control channel domain.

Before the connection is established between the base station and thenarrowband user terminal, the base station may send, according to theposition identifier, the common control information at thetime-frequency position of each sub-control channel domain of the commoncontrol channel domain.

S04: Allocate a random access resource dedicated for the narrowband userterminal and notify the narrowband user terminal in system information.

The narrowband user terminal is notified of the random access resourcein the system information (SI).

The narrowband user terminal obtains the common control information bylistening to a sub-control channel domain and obtains the systeminformation, so as to initiate random access to the base station andestablish the connection with the base station.

S05: After the connection is established, select, according to a channelstate of each sub-control channel domain, a sub-control channel domainwith a channel state that complies with a set standard, notify aterminal user of channel instruction information, and send the dedicatedcontrol information to the narrowband user terminal in the selectedsub-control channel domain.

A channel instruction is information used by the base station toinstruct, according to the channel state of each sub-control channeldomain, the narrowband user terminal to select a sub-control channeldomain.

After the connection is established, the base station may obtain thechannel state of each sub-control channel domain, so as to select thesub-control channel domain that complies with the set standard forsending the dedicated control information to the narrowband userterminal. A method of notifying may be notifying through the sub-controlchannel domain or an RRC message.

Specifically, in this embodiment, the set standard may include a channelpriority, channel connection quality, and/or a channel occupationcondition. For example, a channel with good connection quality and in anidle state may be selected among all the sub-control channel domains, ora sub-control channel domain with a high priority may be selected.

In addition, the base station further sends the channel instruction tothe narrowband user terminal according to the channel state, and thechannel instruction may instruct the narrowband user terminal to listenin the sub-control channel domain that complies with the set standard,so that the narrowband user terminal can communicate with the basestation in a sub-control channel domain with quality assurance.

In this embodiment, a channel state selection scheme is set, so thatwhen sending downlink control information to a narrowband user terminal,a base station selects a sub-control channel domain with good connectionquality and low load and instructs the narrowband user terminal toselect a sub-control channel domain that complies with a set standard,thereby effectively improving reliability of control informationtransmission on a control channel for the narrowband user terminal.

Preferably, in this embodiment, when the physical broadcast channel isextended, a sending manner identifier used for identifying a sendingmanner of the control information in the common control channel domainmay be further included.

To further improve reliability of control information transmission on acontrol channel for the narrowband user terminal, in this embodiment, afrequency hopping manner may be further used for sending the controlinformation for a plurality of times. Therefore, the sending manneridentifier further needs to be added in an extended physical broadcastchannel, so as to indicate the frequency hopping manner for the controlinformation.

When the frequency hopping manner is adopted, the sending the commoncontrol information at the time-frequency position of each sub-controlchannel domain of the common control channel domain may specifically besending, according to the position identifier and in each sub-controlchannel domain in a time-frequency domain of the common control channeldomain, the control information in a sending manner corresponding to thesending manner identifier, so that the narrowband user terminal mayreceive the control information in a corresponding receiving manner andcombine the control information received in a plurality of times,thereby further improving reliability of control informationtransmission.

Further, in this embodiment, the frequency hopping manner mayspecifically include: sending the channel information in differenttimeslots for a plurality of times, or sending the common controlinformation in different sub-control channel domains. In addition, amanner of combining different timeslots and different sub-controlchannel domains may further be adopted, that is, sending same controlinformation at different time-domain resource positions. The narrowbanduser terminal repeatedly receives the control information in acorresponding manner and then combines the received control information.

Further, in this embodiment, control information of paging informationthat is identified as being used for the narrowband user terminal may besent in a sub-control channel domain corresponding to the user terminalaccording to a narrowband identifier preset in the paging information,where the narrowband identifier is used for identifying whether thepaging information is used for the narrowband user terminal.

Further, in this embodiment, the narrowband identifier may not be addedin a paging message, and the control information is sent in a controlchannel domain of a normal user and a control channel domaincorresponding to the narrowband user terminal, so as to ensure receivingof the control information.

After establishing the connection with the base station, the narrowbanduser terminal further listens to the sub-control channel domaincorresponding to the narrowband user terminal in a certain period oftime. Therefore, in a case where the narrowband user terminal is stillin a connection state, when a message arrives, the base station may sendcontrol information corresponding to the message in the correspondingsub-control channel domain according to user terminal information of thenarrowband user terminal and information of the sub-control channeldomain.

When the narrowband user terminal is in an idle (idle) state, when apaging message arrives, the base station determines whether the paginginformation is used for the narrowband user terminal according to anarrowband identifier preset in the paging information, and sends thepaging information used for the narrowband user terminal in thesub-control channel domain corresponding to the narrowband userterminal.

The narrowband identifier may also not be added in the paging message,and the control information is sent in a control channel domain of anormal user and a control channel domain corresponding to the narrowbanduser terminal, so as to ensure receiving of the control information.

A correspondence between the narrowband user terminal and thesub-control channel domain may adopt a plurality of manners, where amanner of a mapping between a user identification of the narrowband userterminal and an identifier of the sub-control channel domain may beadopted, and specifically, the common control channel domain includingtwo narrowband sub-control channel domains A and B is used as anexample:

if UE_ID mod 2=1:

LUE_ID=(UE_ID+1)/2;

then, the narrowband user terminal listens to the sub-control channeldomain A; and

if UE_ID mod 2=0:

then, the narrowband user terminal listens to the sub-control channeldomain B;

LUE_ID=UE_ID/2.

A position of a paging subframe in each sub-control channel domain iscalculated according to the following method:

SFN mod T=(T/N)*(LUE_IDmod N)

i_s=(LUE_ID/N)mod Ns

T=min(Tc,Tue)

N=min(T, the number of paging subframes in each frame * T)

Ns=max(1, the number of paging subframes in each frame)

SFN (system Frame Number) indicates a system frame number, UE_IDindicates an identifier of a narrowband user terminal, LUE_ID indicatesan identifier of a sub-control channel domain, Tc indicates acell-specific default paging cycle in a unit of radio frame, Tueindicates a narrowband user terminal-specific paging cycle with radioframe, N indicates the number of paging frames in a paging cycle, i_sindicates a pointer pointing to a subframe, and Ns indicates the numberof paging subframes in a radio frame for paging. In this way, the pagingmessage is sent in two different sub-control channel domains. Further,to improve transmission reliability of this part of control information,the method may further be modified as: if UE_ID mod 2=1:

first listening to the sub-control channel domain A, and then listeningto the sub-control channel domain B in a next paging subframe; and

if UE ID mod 2=0:

first listening to the sub-control channel domain B, and then listeningto the sub-control channel domain A in a next paging subframe.

A position of a paging subframe in each sub-control channel domain iscalculated according to the following method:

SFN mod T=(T/N)*(UE_IDmod N)

i_s=(UE_ID/N)mod Ns

T=min(Tc,Tue)

N=min(T, the number of paging subframes in each frame * T)

Ns=max(1, the number of paging subframes in each frame)

When sending the paging message, the base station first calculates acorresponding paging subframe according to a method in the prior art,then determines a specific sub-control channel domain according to UE_IDto send corresponding control information of the paging message, andsends the control information of the paging message again in anothersub-control channel domain of a next paging subframe, so as to obtaindiversity gain.

In an embodiment of the present invention, another method fortransmitting control information is further provided, referring to FIG.2, and includes:

S11: Receive an extended physical broadcast channel, and receive commoncontrol information according to a preset position identifier.

By extending a physical broadcast channel, a position identifier usedfor indicating a time-frequency position of a common control channeldomain is added, so as to divide the common control channel domain intoa plurality of narrowband sub-control channel domains. Therefore, thecommon control information may be received according to the presetposition identifier, that is to say, the common control information isreceived in a preset sub-control channel domain, so as to obtain systeminformation.

S12: Initiate random access.

A narrowband user terminal obtains the common control information bylistening to a sub-control channel domain and further obtains the systeminformation, so as to establish a connection with the base station byinitiating random access to the base station.

S13: After a connection is established with a network, report a channelstate, obtain a channel instruction, and listen to a correspondingsub-control channel domain according to the channel instruction.

The narrowband user terminal may obtain a channel state of eachsub-control channel domain, and after the channel state is reported, thebase station may select a sub-control channel domain that complies witha set standard to send control information to the narrowband userterminal.

Specifically, in this embodiment, the set standard may include a channelpriority, channel connection quality, and/or a channel occupationcondition. For example, a channel with good connection quality and in anidle state may be selected among all the sub-control channel domains, ora sub-control channel domain with a high priority may be selected.

In this embodiment, the channel instruction is information used by thebase station to instruct, according to the channel state of eachsub-control channel domain that is reported by the narrowband userterminal, the narrowband user terminal to select a sub-control channeldomain.

Therefore, the base station may further send the channel instruction tothe narrowband user terminal according to the channel state, and thechannel instruction may instruct the narrowband user terminal to listenin the sub-channel control domain that complies with the set standard,so that the narrowband user terminal can communicate with the basestation in a sub-control channel domain with quality assurance.

The channel instruction in this embodiment may be notified by using thesub-control channel domain listened to by the narrowband user terminalor by using an RRC message.

In this embodiment, a channel state selection scheme is set, so thatwhen sending downlink control information to a narrowband user terminal,a base station selects a sub-control channel domain with good connectionquality and low load and instructs the narrowband user terminal toselect a sub-control channel domain that complies with a set standard,thereby effectively improving reliability of control informationtransmission on a control channel for the narrowband user terminal.

Further, in the embodiment of the present invention, a part of contentmay be further added in system broadcast information, including groupingrandom access resources, and establishing a resource-channel mappingbetween each random access resource group and each sub-control channeldomain. The narrowband user terminal is notified of the resource-channelmapping in a sending manner, and the random access resources include atime-frequency resource and a signature sequence that are for randomaccess.

In this way, when initiating random access, the narrowband user terminalmay select, according to a channel condition and/or a priority of eachsub-control channel domain in the common control channel domain, arandom access resource corresponding to a sub-control channel domain toinitiate random access, and listen to the sub-control channel domain.The base station may determine, according to a random access resourceoccupied by a received random access request, the sub-control channeldomain selected by the narrowband user terminal, and send the controlinformation in the sub-control channel domain.

Further, referring to FIG. 3, another embodiment of the presentinvention may further be:

S21: A base station first configures a preset default manner to divide anarrowband control channel domain, where the preset default mannerincludes a default time-frequency position of each sub-control channeldomain, that is, presets a position identifier of each sub-controlchannel domain.

S22: A narrowband user equipment terminal accesses a network by usingthe default receiving manner.

S23: The base station configures, for the narrowband user terminal, adedicated frequency hopping manner for receiving a sub-control channeldomain.

S24: The narrowband user terminal performs channel measurement whenlistening to a corresponding sub-control channel domain and reportschannel quality of the sub-control channel domain.

S25: After receiving a corresponding channel quality report, the basestation side selects a sub-control channel domain with good channelquality to send new control information, and notifies a correspondingnarrowband user terminal of a position identifier of the new sub-controlchannel domain, that is, sends a channel instruction to the narrowbanduser terminal. The new sub-channel control domain may also adopt aworking manner of frequency hopping between a plurality of sub-controlchannels. A manner of notifying the narrowband user terminal of a changeof the sub-control channel domain may be notifying by using a defaultPDCCH, or by using an RRC message (for example, RRCConnectionSetup,RRCConnectionReconfiguration, and RRCConnectionReestablishment). FIG. 4shows a manner of notifying by using an RRC message.

In this embodiment, a downlink channel quality report may also bereplaced with a mapping between a random access resource and asub-control channel domain.

Further, referring to FIG. 5, another embodiment of the presentinvention may further be:

S31: A base station first configures a default frequency hopping mannerto configure a sub-control channel domain.

S32: A narrowband user terminal accesses a network by using the defaultfrequency hopping manner, performs channel measurement when listening tothe sub-control channel domain by frequency hopping, and reportscorresponding channel quality.

S33: After receiving a corresponding channel quality report, the basestation selects a sub-control channel domain with good channel qualityto send new control information, and notifies a corresponding narrowbanduser terminal of position information of the new sub-control channeldomain. The new sub-channel control domain may also adopt a workingmanner of frequency hopping between a plurality of sub-control channels.A manner of notifying the narrowband user terminal of a change of thesub-control channel domain may be notifying by using a default PDCCH, orby using an RRC message (for example, RRCConnectionSetup,RRCConnectionReconfiguration, and RRCConnectionReestablishment). FIG. 6shows a manner of notifying by using an RRC message.

In this embodiment, a downlink channel quality report may also bereplaced with a mapping between a random access resource and asub-control channel domain.

Finally, it should be noted that the foregoing embodiments are merelyintended for describing the technical solutions of the embodiments ofthe present invention rather than limiting the present invention.Although the embodiments of the present invention are described indetail with reference to the foregoing embodiments, persons of ordinaryskill in the art should understand that they may still makemodifications to the technical solutions described in the foregoingembodiments or make equivalent replacements to some technical featuresof the technical solutions. However, these modifications or replacementsdo not make the essence of the technical solutions depart from thespirit and scope of the technical solutions of the embodiments of thepresent invention.

What is claimed is:
 1. A method, comprising: receiving, by a userterminal according to a preset position identifier, common controlinformation in a sub-control channel domain, wherein a common controlchannel domain is divided into a plurality of sub-control channeldomains, the preset position identifier identifies the sub-controlchannel domain, and the sub-control channel domain is one of theplurality of sub-control channel domains; initiating, by the userterminal according to common control information, random access; after aconnection is established with a base station, reporting, by the userterminal to the base station, a channel quality state of eachsub-control channel domain of the plurality of sub-control channeldomains; receiving, by the user terminal, a channel instruction from thebase station, wherein the channel instruction indicates a selectedsub-control channel domain in the plurality of sub-control channeldomains; and listening, by the user terminal according to the channelinstruction, to the selected sub-control channel domain.
 2. The methodaccording to claim 1, wherein the common control information comprises:control information used for scheduling system information (SI), controlinformation used for scheduling a paging message, and controlinformation used for scheduling a random access response message.
 3. Themethod according to claim 1, wherein the channel instruction is receivedusing the selected sub-control channel domain listened to by the userterminal.
 4. The method according to claim 1, wherein the channelinstruction is received using a default physical downlink controlchannel (PDCCH).
 5. The method according to claim 1, wherein the channelinstruction is received using a radio resource control (RRC) message. 6.A user terminal, comprising: a receiver; a transmitter; and a processor;wherein the receiver is configured to receive, according to a presetposition identifier, common control information in a sub-control channeldomain, wherein a common control channel domain is divided into aplurality of sub-control channel domains, the preset position identifieridentifies the sub-control channel domain, and the sub-control channeldomain is one of the plurality of sub-control channel domains; whereinthe processor is configured to initiate, according to the common controlinformation, random access; wherein the transmitter is configured toreport, to a base station, a channel quality state of each sub-controlchannel domain of the plurality of sub-control channel domains afterestablishing a connection with the base station; wherein the receiver isfurther configured to receive a channel instruction from the basestation, wherein the channel instruction indicates a selectedsub-control channel domain in the plurality of sub-control channeldomains; and wherein the processor is configured to listen, according tothe channel instruction, to the selected sub-control channel domain. 7.The user terminal according to claim 6, wherein the common controlinformation comprises: control information used for scheduling systeminformation (SI), control information used for scheduling a pagingmessage, and control information used for scheduling a random accessresponse message.
 8. The user terminal according to claim 6, wherein thechannel instruction is received using the selected sub-control channeldomain listened to by the user terminal.
 9. The user terminal accordingto claim 6, wherein the channel instruction is received using a defaultphysical downlink control channel (PDCCH).
 10. The user terminalaccording to claim 6, wherein the channel instruction is received usinga radio resource control (RRC) message.
 11. An apparatus, comprising: aprocessor coupled with a non-transitory storage medium storingexecutable instructions, wherein the executable instructions, whenexecuted by the processor, cause the apparatus to: receive, according toa preset position identifier, common control information in asub-control channel domain, wherein a common control channel domain isdivided into a plurality of sub-control channel domains, the presetposition identifier identifies the sub-control channel domain, and thesub-control channel domain is one of the plurality of sub-controlchannel domains; initiate, according to the common control information,random access; after a connection is established with a base station,report, to the base station, a channel quality state of each sub-controlchannel of the plurality of sub-control channel domains; receive achannel instruction from the base station, wherein the channelinstruction indicates a selected sub-control channel domain in theplurality of sub-control channel domains; and listen, according to thechannel instruction, to the selected sub-control channel domain.
 12. Theapparatus according to claim ii, wherein the common control informationcomprises: control information used for scheduling system information(SI), control information used for scheduling a paging message, andcontrol information used for scheduling a random access responsemessage.
 13. The apparatus according to claim ii, wherein the channelinstruction is received using the selected sub-control channel domainlistened to by the apparatus.
 14. The apparatus according to claim ii,wherein the channel instruction is received using a default physicaldownlink control channel (PDCCH).
 15. The apparatus according to claimii, wherein the channel instruction is received using a radio resourcecontrol (RRC) message.